E. coli Cell Bank Characterization Services
E. coli cell bank release testing is essential for biopharmaceutical production of plasmids and therapeutic proteins. Regulatory agencies require thorough characterization of the identity, purity, and genetic stability of the E. coli cell banks used in GMP manufacturing. This ensures the cell bank is contaminant-free, genetically stable, and possesses the necessary characteristics for reliable and safe bioprocesses.
E. coli Pre-bank Testing
Critical Quality Attributes
Assay
Description
Lytic Phage Detection
Microbiological assay to test for presence of lytic phage in cell bank
Purity
Lysogenic Phage Detection
Microbiological assay to test for presence of lysogenic phage in cell bank
Phage ID Confirmation
Confirmation of phage identity by NGS
Identity
Plasmid Sequencing
Confirmation of full or partial sequence of the plasmid by Sanger sequencing or NGS
E. coli Cell Bank Testing (CGMP)
Critical Quality Attributes
Assay
Description
Identity
Species ID
Confirmation of bacterial species using bioMerieux API20E test
Plasmid Sequence Confirmation
Confirmation of full or partial sequence of the plasmid by Sanger sequencing or NGS
Strain ID
Various biochemical tests to confirm the strain’s genotype based on phenotypic characteristics
Identity
Species ID
Confirmation of bacterial species using bioMerieux API20E test
Gram Staining
Confirmation of Gram Stain phenotype of bacterial cell bank
Colony Morphology Testing
Confirm morphology of colonies after expansion of cells on agar plates
Purity
Lytic Phage Detection
Microbiological assay to test for presence of lytic phage in cell bank
Purity Testing
Test for aerobic and anaerobic bacteria and aerobic fungi in cell bank
Purity
Lytic Phage Detection
Microbiological assay to test for presence of lytic phage in cell bank
Lysogenic Phage Detection
Microbiological assay to test for presence of lysogenic phage in cell bank
Stability
Plasmid Gene of Interest Sequence Confirmation
Confirmation of full or partial sequence of the plasmid in MCB, WCB, and EOPC by Sanger sequencing
Marker Retention
Determine percentage of cells capable of maintaining selectable marker/plasmid
Plasmid Copy Number
Quantify copies of plasmid per cell in MCB, WCB, and EOPC by QPCR or ddPCR
Stability
Plasmid Gene of Interest Sequence Confirmation
Confirmation of full or partial sequence of the plasmid in MCB, WCB, and EOPC by Sanger sequencing
Viability Testing
Determine percentage of viable cells in cell bank (cfu/ml)
mRNA Sequencing
Sequencing of the target gene of protein expression in MCB, WCB, and EOPC by Sanger sequencing
Other E. coli Cell Bank Testing
Critical Quality Attributes
Assay
Description
Other
16S rRNA Sequencing
Identification of Bacterial species by 16S/ITS Sequencing by Sanger
Antibiotic Sensitivity Testing
Confirmation of antibiotic resistance in E. coli cell bank
Other
16S rRNA Sequencing
Identification of Bacterial or Fungal species by 16S/ITS Sequencing by Sanger
E. coli Genome Confirmation
Confirmation of full or partial E coli genome by NGS
Phage ID Confirmation
Testing for line clearance of residual plasmid using TaqMan assays targeting Kanamycin or other plasmid sequences in between plasmid batch production by QPCR